Re: [PATCH v2 5/9] vgacon: remove screen_info dependency

[Arnd Bergmann]

On Wed, Jul 19, 2023, at 15:49, Philippe Mathieu-Daudé wrote:
> On 19/7/23 14:39, Arnd Bergmann wrote:

>> @@ -1074,13 +1077,13 @@ static int vgacon_resize(struct vc_data *c, unsigned int width,
>>   		 * Ho ho!  Someone (svgatextmode, eh?) may have reprogrammed
>>   		 * the video mode!  Set the new defaults then and go away.
>>   		 */
>> -		screen_info.orig_video_cols = width;
>> -		screen_info.orig_video_lines = height;
>> +		vga_si->orig_video_cols = width;
>> +		vga_si->orig_video_lines = height;
>>   		vga_default_font_height = c->vc_cell_height;
>>   		return 0;
>>   	}
>> -	if (width % 2 || width > screen_info.orig_video_cols ||
>> -	    height > (screen_info.orig_video_lines * vga_default_font_height)/
>> +	if (width % 2 || width > vga_si->orig_video_cols ||
>> +	    height > (vga_si->orig_video_lines * vga_default_font_height)/
>>   	    c->vc_cell_height)
>>   		return -EINVAL;
>>   
>> @@ -1110,8 +1113,8 @@ static void vgacon_save_screen(struct vc_data *c)
>>   		 * console initialization routines.
>>   		 */
>>   		vga_bootup_console = 1;
>> -		c->state.x = screen_info.orig_x;
>> -		c->state.y = screen_info.orig_y;
>> +		c->state.x = vga_si->orig_x;
>> +		c->state.y = vga_si->orig_y;
>
> Not really my area, so bare with me if this is obviously not
> possible :) If using DUMMY_CONSOLE, can we trigger a save_screen
> / resize? If so, we'd reach here with vga_si=NULL.
>

I think it cannot happen because the only way that anything calls
into vgacon.c is through the "conswitchp = &vga_con;" that now happens
at the same time as the "vga_si = &screen_info;". It's definitely
possible that I'm missing something as well here.

     Arnd